Fastening device



1 1 J. P. FRANCIS I 2,873,007

FASTENING DEVICE FiledFeb. 10, 1955 INVENTOR J5 R 6? as ATTOR United States Patent "ice,

(GrautediunderTitle 35,..U.S. Code 1952 semen The invention .described'herein may, be manufactured andused by or for the .Governmentof the :United .S.tates of America for governmental purposes withoutthe: payment of. any royaltiesthereon ortherefor.

This invention relates tofasteningdevices, and-more particularly, to .detachable fastening devices which are .adapted tolsecure two or more. members-whichare ac- .cessible from-only. one side.

It isean. object of thisinve'ntion to-provideaifas tening device which positively locks parts together. v

.It is a, further. object of..thisinventionto provide a- "fastening .device which is. quickly .and .easily lockedtand "unlocked.

*It isastilhfurther-object .ofthis invention. to provide a fastening. device whichdsl simple in .construction' and tip .eration.

llOjthen'objects'.andemany of. the attendant. advantages [of this. invention will belreadily: appreciated. asthe. same becomes; better. understood. by reference to the following detailed. description when considered. in. connection with (:the. accompanying drawings wherein:

'T Fig. l. is anelevation and sectional viewho f. a.fastening device employingithe principles ofithi'siuyention;

"Fig; 2.,is. an elevation andsectional NiBW. of; a..pre'ferred embodiment of a fastening device employing .the ;prin- .ciples of this invention;

Fig. 2a. is a. detailed.sectibnallview. of. aportion. ofthe f fastening devices'hown in Fig. 2;

Fig; 3 isan"elevationaliviewnofaimodificationofthe I preferred embodiment shown infFig.'2; and

I"Fig.'4 is a bottom plan .ofjthe couplingasapplieddo the coupled plates, withjthe. bolt. 16 omitted.

"Referring now to FigJil, .two, ,or moreiplates, .suchas plates 10,12," and 14; havingjholes therein located; in

.cooperative relationship with respect -to. eachother, are

secured by bolt '16.. 'The'forwa'rd endl 18.01. bolt v16 is l in the shape of a cam surface which is. atan obliqueangle with-respect t-o.the axis of b1olt11'6. Cut into-bolt .161 is cam surfaced oblique groove 20 so that. the. innerlendeof the groove is offset from the. .entranceendof'thegronve, andhencethe inner end of thegrovedsundercutwith respect ,to its outer end. The inner .end ofIIhe, groove. is nearer the oblique end lsythan is'the entranceend of..the

groove. Both the cam surfaces-offorwardmend.18 .of .bolt 16 and ,groove 20. are. symmetricaljabout.a,..given plane including'the axis of bolt 16. Engaged by groove .20 is locking bar 22 -(Eig. 4.als whichisl-pivotally mounted on plate 14 at point' 24.. The other end ofdocking' bar 22 is connected by a .tension spring 28ito'pin 26 which, is attached'to plate 14. Pin 30, whiclii's' attached gto plate 14,' provides astop, for locking bar-.22. .Nut32 and washer'34 onjthread'edflendi 3'6 ofjbblt 16 ,provides an adjustable. head for ,boltl6.

Referring now to.the.,operation of. the zfastcning ,-device lshowu in Fig....l upon insertion v.of bolt.16. a .s1ight:presv.sure is. applied .to..threaded .,end.26. .This causes. camsurfaced forward end 18 to rotate locking bar 22 outward sishoulderi50 on collar 44.

': Patented: Feb. 10, 51959 a i 2 aagainst-theitension of'spring 28. When bolt 16 reaches dthe pointxwhere locking bar 22 is level with groove 20, locking bar:.22is moved into groove 20 by'the tension of .cspring28. rThe pressure on end 36 is then released. The ..-cam surfaces of groove'20 and thetension-of spring 28 causetlo'cking bar122 to move-to the bottom of groove 20, ;.p.ositiv.ely lockingbolt' 16 against rotation. Nut 32 -is .thenltightened forcing wa'sher 34 against plate 10.

To detach the fastening device, nut 32 is loosened, PECSSlll'fiiiS appliedtonthreaded end 36, causing locking v.bari22:to;moveup and out ofgroove'zll; then bolt 16-is -:ti1r=ned:t90,.- so "that locking bar'i22 cannot re-engage .-:groove 2.0,sandibolt 16'is .removed; 1

1 Referring 'nowxto' Figs. 2.:and 241, like reference numerals are used to identify like parts shown .in' Fig. 1. Theifasteningtdeviceshown in Figs. 2 and his similar to tithe fasteningdeviceshown in Fig. 1, except th'at-nut 32 :txand washer..-34xare replaced by bevelled head 38, which ::is axiall'yzmovable withzrespect to bolt 16.

Bevelled headt38 is provided with collar 44 at the lower extremity; thereof and bolt 16- is provided with' ascrew- ;driverislot 40: on :top .thereof. Top: plate 10a is bent to .form :recess'i42' for receiving bevelled head 38, -so that :theitop tsurfaceofxbeyelled headi38 isinormally flush with *sthe top'suifacezofiplate 10a. Spring 46, located between qEbolt-zil'fix-and bevelledJhead 38,- is supported at one end iziby 'iShOllldEL' i482i0l1ib01l2.16 and at the other end by iliabsu52:a1id*:54 maybe provided, if desired, for-restaining; bevelledihead. 38'. and bolt 16, respectively. However; thesezitabsimay be omitted, in which: case; bevelled nh'eadiB-S and bolt;16 are removable.

-- i."llo..-op,erate:1the :fasteningvdeviceshownin Figs. 2and 2a,:bolt.16ispressedadbwnward with a screw-driver, ecompressing spring 46,.whereby lockingbar 22 is engaged -;in-groove: 20 inthe same, manner as in the fastening device. of Fig.51. i'Pressure' on. bolt 16' isithen. removed,

iiwhereupon spring a 46 automatically pushes bolt 16" back toward its originalcposition, locking .locking-bar22= -in '-=groove:;20. To-release locking bar..22, bolt 16 ispressed .Edownward and rotated'90." asin Fig. 1, andthen allowed to return:to ritsloriginahposition by spring 46.

'aFDhe kfastening-"devicez shown in: Fig. '3j-is essentially similar in structurelandoperation to :the fastening device showmin FigsJZiand 2a. The. only diiference is. that spring 46a is externally located with. respect to =bevelled head-38 andicollar 44 is; omitted. Spring 46a ha's one -end thereof connectedto bevelled head138 and theother vendthereof connected to-bolt 16. Pin 56 is provided for :lim'iting ithe upward. movement of bolt .16 relative: .to

b'evelledihead=38.

Obviously==many modifications and variations ofthe present. (invention are: possible .in theclight of :the above teachings. It is -theref0re:to:be understood that within the scope of thekappended claims the inventionmay" be ,practiced .otherjwise 'than as specifically "described.

-I- claim: 11.: Int-combination, a plate like member having a hole, -a-.locking bar, one end of said locking bar being pivotally 1 :secured: to said plate like member. adjacent the hole" for movement. about an :axis substantially perpendicular :to said plate-likemembensaid lockingbar extending:transversely-relative to its: pivot axisand closeto and-parallel with: theadjacent. face of said member whereby it :is adaptedito. assumecneposition whe'reiit extends across ;the "hole: and another position arcu'atelyspaced therefrom about its-pivot axis'where'tit does not extend across-the "111016, meansv including stop means and spring means se- -curedzto;plate=like:member adjacent said hole andto the other end 0f said :locking barifor normally retaining s'a'id flocking: bar in SaldYOIIEij position; a: beltlofi slightly smaller diameter than the hole having a head at one end thereof which is movable axially of said bolt and which 'is of greater dimension thanthe diameter ,of the hole, said bolt formed with a transverse groove adjacent its other end extending into said bolt toward its said other end obliquely relative to the axis of said bolt, said other end of said bolt being formed as a cam surface substantially parallel to the transverse. groove, said bolt being adapted to removably fasten said plate-like member to another plate-like member having a similar sized hole.

2. The combination defined in claim 1, further including a spring wound around said bolt and having one end engaging said bolt and the other end engaging said head.

3. The combination defined in claim 2, wherein said spring is located within said head and wherein said bolt has a shoulder at saidone end thereof for supporting one end of said spring and said head has a shoulder at the forward end thereof for supporting the other end of said spring. 1

4. A fastening device for attachment of a member to one face of a plate where the other face of said plate is inaccessible for completion of the coupling, and which device has maximum compactness in the direction of the thickness of the plate, comprising said plate with an aperture therethrough, a stud movable endwise and rotatable in said aperture and projecting through and beyond said plate at said inaccessible face, the projecting end of said stud having a notch in a side thereof, which notch extends only part way around said stud leaving an un-' its inaccessible face and extending therefrom across the open end of said aperture and close to and along said inaccessible face, said bar being resiliently urged into its position transversely across said aperture end and into said notch in said stud when the notch is aligned therewith and facing it, the projecting end of said stud at said inaccessible face being oblique to engage and cam aside said bar as the stud is inserted through said aperture in said plate, said stud and member having'cooperating parts by which attachment of the stud to said plate will couple said member to said plate.

5. The device as set forth in claim 4 wherein said memher is another plate abutting face to face against said one plate at its accessible side, and said cooperating parts are a shoulder on said stud abutting against said another plate and confining it to said one plate.

6. The device as set forth in claim 4, and meansresiliently urging said stud in a direction tending to withdraw it from said plate and thereby maintainng pressure contact between said stud and the bottom of said notch in said bar, and said notch being undercut at-its bottom relatively to its open end and preventing rotation of said stud and until the stud has been moved endwise against the action of said resiliently urging means to align the bar transversely with the entrance to said notch.

7. The device as set forth in claim 5, and means resiliently urging said stud in a direction tending to withdraw it from said plate and thereby maintaining pressure contact between said stud and the bottom of said notch in said bar, and said notch being undercut at its bottom relatively to its open end and preventing rotation of said stud until the stud has been moved endwise against the action of said resiliently urging means to align the bar transversely with the entrance to said notch.

8. A fastening device for coupling together two plates abutting face to face, where one exposed face of one plate is inaccessible to complete the coupling, and which has maximum compactness in a direction normal tothe faces of the plates, comprising said plates abutting face to face with aligned apertures from face to face of the plates, a stud received in and passing through said apertures, movable endwise and also rotatable in the apertures, and with an end projecting beyond said inaccessible face of said one plate, said projecting end having an end face oblique to the axis of the stud and a notch in the side of the projecting end, which notch extends only partway around said stud leaving an unnotched part of the side of the stud approximately axially aligned with said notch, locking means for said stud having a bar attached at one end to said one plate at its inaccessible face and biased to extend in close proximity and parallel to said inaccessible face across the space occupied by said projecting stud end and bear against a side of said stud when the stud is in said apertures and enter said notch when the notch is facing and aligned with said bar, means cooperating with the Outer end of said stud for engaging the other of said plates on its exposed face to confine said other plate to said one plate whereby rotation of said stud in said apertures of said plates while said bar is aligned transversely with the outer open end of sald notch will cam said bar out of said notch enabling removal of said stud to uncouple said plates, and said oblique end face of said projecting end of said stud, when the stud is inserted through said plates in said apertures will cam said bar aside until said stud notch is aligned with and faces said bar, enabling the bar under its bias to enter the notch and lock the stud in place.

' means cooperating with the outer end of the stud is countersunk approximately flush in the exposed face of said other plate to reduce the overall thickness of the plates and the coupling of the same together.

10. The device as set forth in claim 8, and a spring acting between said cooperating means and said stud and urging said stud'in a withdrawal direction to maintain pressure between said bar and a side of said notch.

11. The device as set forthin claim 8, and a spring acting between said cooperating means and said stud and urging'said stud in a withdrawal direction to maintain pressure between said bar and a side of said notch, and said notch in said stud being undercut at its bottom relatively to its entrance end and in the direction of the length of said stud in the bottom of which undercut said bar is engaged under the action of said spring on said stud, whereby endwise inward movement of said stud is required before it can be rotated to cam said bar aside and release itself.

12. The device as set forth in claim 8, wherein said means cooperating with the outer end of the stud includes a member surrounding the stud, countersunk approximately fiush in the outer face of said other plate and having an internal flange at its inner end, said stud at its outer end has an external shoulder approximately flush with the outer face of said member, and a helical spring surrounding said stud and compressed between said flange and said shoulder.

- 13. The device as set forth in claim 8, wherein said means cooperating with the outer end of the stud includes 'a member surrounding the stud, countersunk approxisaid flange and said shoulder, the outer end of said stud being formed to receive a tool by which the stud may be pressed endwise and rotated to release itself from said bar.

14. The device as set forth in claim 8, wherein said means cooperating with the outer end of the stud includes a member surrounding the stud, countersunk approximately flush in the outer face of said other plate and having an internal flange at its inner end, said stud at its outer end has an external shoulder approximately flush endwise and rotated to release itself from said bar, said notch in the stud being undercut at its bottom relatively to its open end and the length of said stud in which undercut said bar is engaged under the action of said spring on said stud, whereby said endwise movement of said stud is required to move the non-undercut part of said notch into alignment with said bar before the stud can be rotated to carn the bar aside and release itself from said bar for endwise withdrawal from the plates.

15. A fastening device for coupling together two plates in a face to face relation through aligned apertures in the plates, where one outer face of one of the assembled plates is inaccessible to establish the coupling between the plates, which comprises said plates in face to face relation with aligned apertures, a locking bar secured at one end to said one plate on its said inaccessible face and extending therefrom parallel and close to said inaccessible face across said aligned apertures if axially extended, means resiliently urging the free part of said bar into said position across said aligned apertures and yieldingly holding it there, a stud disposed in said aligned apertures, extendng through both of said plates, rotatable about the axis of the apertures and movable endwise axially along the apertures, the end portion of said stud beyond the aperture end in said one plate at said inaccessible face having in one side thereof a notch into which said bar may move to prevent withdrawal of said stud, said notch extending only part way around the circumference of said stud, means by which said stud may be moved endwise in a direction to withdrawit from said aligned apertures at the accessible face when permitted by removal of said bar from said notch in said stud, the extreme end face of said end portion of the stud being oblique to the longitudinal axis of the stud, whereby when the stud is inserted into said apertures, with said oblique end first, the oblique end face of the stud will cam said bar aside and hold it aside until the bar and notch are aligned and the bar can enter the notch to lock the stud against removal from said plates.

16. The device as set forth in claim 8, wherein said notch has both side walls oblique to the axis of the stud and its inner end out of transverse alignment with the end entrance to the notch, and said means cooperating with the outer end of said stud and said stud are relatively movable endwise of the stud to cause endwise movement of the stud in said apertures with camming of the locking bar out of the notch by the oblique side walls during such endwise movement.

17. In combination; a pair of plates to be connected together face to face and having aligned apertures, a thin, rod-like locking bar having a right angular end portion pivoted to one exposed face of one of said plates with its axis of pivoting perpendicular to a face of that plate and with the balance of the bar extending parallel and close to said exposed face; a bolt having a head at one end thereof which is movable axially of said bolt, and also having a transverse groove adjacent its other end and extending into said bolt toward its said other end, with both side Walls of the groove oblique relative to the axis of said bolt and generally parallel to one another, said other eud of said bolt being formed as a cam surface oblique to the length of the bolt, and operable when the bolt is inserted through the aligned apertures to cam the locking bar aside, a stop pin on said one face of said one plate and spring means connected to said one plate and to said locking bar and urging said bar into a position against said stop, said stop limiting movement of said bar to a position partly across said plate apertures whereby when said bolt is inserted through the apertures in both plates, cam end first, as its cam end moves to project beyond the holes it will force said locking bar by cam action away from across said apertures until it snaps into said groove in said bolt, and locks the bolt against removal until the bolt is first moved endwise to cam the locking bar out of the notch and then rotated to place the unnotched side of the bolt against said bar and enable removal of the bolt.

References Cited in the file of this patent UNITED STATES PATENTS 2,252,286 Hathorn Aug. 12, 1941 2,526,791 Wroblewski Oct. 24, 1950 FOREIGN PATENTS 266,964 Great Britain Mar. 10, 1927 538,115 Great Britain July 22, 1941 

